Fuel cells are beginning to gain a foothold as a source of electricity for heating, ventilation, air conditioning and refrigeration equipment (HVAC&R). Thus, a fuel cell may be used as a primary source of electricity, such as in isolated areas where an electric utility is not reliably established, such that all of the electrical power to an HVAC&R system is provided by the fuel cell alone. It may also be used as a supplementary source of electricity during emergencies such as, for example, blackouts or power failures due to weather conditions and the like as well as during excessive loading of the power grid or limitations of existing conventional power supplies.
At present, fuel cells are approximately 40-50% efficient, so there is a substantial amount of heat generated by the fuel cell during its operation. A large percentage of this heat may be lost as waste heat. Some components of fuel cells operate at high temperatures and, at certain operating conditions, may even require special cooling systems.
Heating systems that are installed in commercial buildings, residences, restaurants, hospitals and the like are of various types which include heat pumps, hydronic or hot water systems, steam systems, and hot water heaters. In the case of hydronic/hot water heat, steam heat and hot water heaters, the source of heat is commonly natural gas, fuel oil or the like, which, in recent years, has become relatively expensive. In the case of heat pumps, it is typically electrical energy that is utilized to power heat pump components such as compressors, fans, liquid pumps and controls. However, in such systems, a phenomenon known as “cold blow” occurs and is typically associated with low temperature ambient conditions. During these periods of time, it is necessary to operate electrical resistance heaters or strip heaters to supplement the primary heat pump heating system and to heat the air to a desired temperature that would otherwise enter a heated space and be sensed by an occupant of that heated spaces as an uncomfortably “cold air”.
What is needed is a method/apparatus for reducing the “cold blow” phenomenon and for the efficient recovery of heat that might otherwise be lost as waste heat.